<!doctype html>
<html>
<head>
  <meta charset="UTF-8">
  <meta name="viewport" content="width=device-width, initial-scale=1.0">
  <style>
    .section {
      display: flex;
      justify-content: center;
      flex-direction: column;
      align-items: center;
    }
  </style>
</head>
<body>
  <section class="section">
    <div>
    <h1><a href="./1-simple-error.html">Demo-1: Simple Error</a></h1>
  </div>
  <div>
    <h1><a href="./2-404-with-footer.html">Demo-2: 404-with-footer</a></h1>
  </div>
  <div>
    <h1><a href="./3-404-center.html">Demo-3: 404-in-center</a></h1>
  </div>
</section>  
</body>
</html>